Cobalt-Salen Catalyzed Electroreductive Alkylation of Activated Olefins

Table 2

Results of the reductive coupling reaction of 2-bromooctane with methylvinylketone in various solvents under CoCl₂+ H₂Salen catalysis.

Run	Solvent	Yield^a
1	DMF	51%
2	DMF + NH4Cl^b	55%
3	DMF/EtOH (8/2)	46%
4	DMF/EtOH (1/1)	59%
5	DMF/EtOH (3/7)	22%
6	EtOH	4%
7	DMF/MeOH (1/1)	15%
8	DMF/AN (1/1)	46%
9	AN	Traces

Experimental conditions: anode = Fe; cathode = Ni grid (surface area = 30 cm²); current intensity I = 0.1 A; supporting electrolytes: TBABr (10⁻² mol·L⁻¹) + TBAI (8.10⁻³ mol·L⁻¹); catalyst: CoCl₂ (9.4.10⁻² mol·L⁻¹) + H₂Salen (9.4.10⁻² mol·L⁻¹); T = 60°C; 2-bromooctane = 0.1875 mol·L⁻¹; methylvinylketone = 0.47 mol·L⁻¹; ^aGC yield, with ethyl undecanoate as internal standard; ^bNH₄Cl was used as supporting electrolyte (5.10–2 mol·L⁻¹) and as proton source.